Search for the decay Bs0 -> mu mu with the ATLAS detector

TL;DR

This study conducted a search for the rare decay Bs0 -> mu mu using ATLAS data from 7 TeV proton-proton collisions, setting upper limits on its branching fraction due to no observed excess.

Contribution

First search for Bs0 -> mu mu decay with ATLAS at 7 TeV, establishing upper limits on the decay's branching fraction.

Findings

No excess events observed over background

Upper limit on BR(Bs0 -> mu mu) < 2.2 x 10^(-8) at 95% CL

Data consistent with Standard Model predictions

Abstract

A blind analysis searching for the decay Bs0 -> mumu has been performed using proton-proton collisions at a centre-of-mass energy of 7 TeV recorded with the ATLAS detector at the LHC. With an integrated luminosity of 2.4 fb^(-1) no excess of events over the background expectation is found and an upper limit is set on the branching fraction BR(Bs0 -> mu mu) < 2.2 (1.9) x10^(-8) at 95% (90%) confidence level.